Nigeria's free digital learning hub. Videos, lecture notes, practice questions and leaderboards aligned with CCMAS, NBTE, NCCE, WAEC, NECO, IJMB and JAMB curricula.
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Nigeria's free digital learning hub. Videos, lecture notes, practice questions and leaderboards aligned with CCMAS, NBTE, NCCE, WAEC, NECO, IJMB and JAMB curricula.
Environmental Health Science · 300 Level
This is the complete lecture note for EVM 308 Computer application in environmental management, prepared for Environmental Health Science students at 300 Level. You can read it online below, open it in the full viewer, or download the PDF for offline study. It pairs with the course's video lectures, so you can read and watch together.
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS Series 1 Course code: EVM308 Course title: Computer Application in Environmental Management Course credit load: 3 Units List of Series: Series 1: Basic Techniques of Map Making Series 2: Cartographic Devices and Environmental Data Gathering Series 3: Visual Presentation of Statistical Sources Series 4: Scale, Error Factors, and Map Design Series 5: Conceptual and System Diagrams in Environmental Management Series 1: Basic Techniques of Map Making Series Outline Part 1 (1.1): Introduction to Maps and Map Making Sub-Part 1.1.1: Definition and purpose of maps Sub-Part 1.1.2: Types and classification of maps Part 2 (1.2): Basic Elements of a Map Sub-Part 1.2.1: Title, scale, and north arrow Sub-Part 1.2.2: Legend, symbols, and grid references Sub-Part 1.2.3: Projection systems and coordinate grids Part 3 (1.3): Map Drawing Techniques Sub-Part 1.3.1: Freehand and instrumental drawing Sub-Part 1.3.2: Computer-assisted map drawing Part 4 (1.4): Map Reading and Interpretation Sub-Part 1.4.1: Reading contour lines and relief features Sub-Part 1.4.2: Interpreting environmental data from maps Sub-Part 1.4.3: Applications of map reading in environmental management Part 5 (1.5): Geographic Information Systems and Environmental Mapping Sub-Part 1.5.1: Introduction to GIS and its components
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS Sub-Part 1.5.2: Producing maps using GIS software Sub-Part 1.5.3: GIS applications in environmental management in Nigeria Introduction Maps are among the most powerful tools available for recording, analysing, and communicating information about the environment. From the earliest hand-drawn sketches to modern computer-generated outputs, maps have enabled people to understand their surroundings, plan land use, manage natural resources, and respond to environmental challenges. In computer-aided environmental management, the ability to make, read, and interpret maps is a core professional competency that applies across virtually every area of practice. This Series introduces you to the foundational knowledge and techniques you need to work effectively with maps. The aim of this Series is to equip you with a thorough grounding in the basic techniques of map making, including the types and elements of maps, the methods used to draw them, the skills required to read and interpret them, and the growing application of Geographic Information Systems (GIS) in environmental mapping in Nigeria. We shall commence this Series by exploring the concept and purpose of maps, including their definitions and the various types in use. Next, we will examine the essential elements that make up a well-designed map, such as the title, scale, north arrow, legend, symbols, and grid references. We will then move on to the techniques used to draw maps, covering freehand and instrumental methods as well as computer-assisted approaches. Afterwards, we will develop your skills in reading and interpreting maps, focusing on contour lines, environmental data, and practical applications. Finally, we will round off by introducing Geographic Information Systems (GIS), their components, and their applications in environmental mapping in Nigeria. Series Learning Outcomes Upon completing this Series, you should be able to: SLO 1.1 define the concept of a map and describe the major types and classification of maps, SLO 1.2 identify and explain the basic elements that constitute a well-designed map, SLO 1.3 apply freehand, instrumental, and computer-assisted techniques in drawing maps, SLO 1.4 read and interpret topographic maps, including contour lines and environmental data, SLO 1.5 evaluate the role of GIS in environmental mapping and management in Nigeria.
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS 1.1 Introduction to Maps and Map Making 1.1.1 Definition and purpose of maps A map is a graphic representation of the earth’s surface, or part of it, drawn to a specified scale on a flat surface. Maps serve a wide range of purposes: they help you navigate unfamiliar terrain, understand the spatial distribution of natural resources, plan land use, monitor environmental change, and communicate geographic information to diverse audiences. In environmental management, maps are indispensable for tasks such as identifying flood-prone areas, tracking changes in forest cover, documenting vegetation zones, and planning conservation activities. Every map is a selective and simplified picture of reality, highlighting features relevant to its purpose while leaving out others. When you work with a map, you are reading a carefully designed language of symbols, colours, and scales intended to convey spatial information efficiently. In Nigeria, maps are produced by the Office of the Surveyor-General of the Federation, the National Space Research and Development Agency (NASRDA), and numerous research and planning institutions, and they are used daily in environmental management, urban planning, and disaster response. When rainfall intensity exceeds the soil’s ability to absorb water, erosion is accelerated. Similarly, wind erosion is more severe in areas with sparse vegetation cover. Fill in the blank: A graphic representation of the earth’s surface drawn to scale on a flat surface is called a __________. Diagram illustrating the major purposes of maps in environmental management Figure 1.1 Major purposes and applications of maps in environmental management
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS 1.1.2 Types and classification of maps Maps can be classified in many ways depending on their content, scale, and purpose. Topographic maps show the physical features of the landscape, including elevation, rivers, forests, and settlements, using contour lines to represent relief. Thematic maps focus on a specific subject such as vegetation cover, population density, land use, or rainfall distribution. Cadastral maps are large-scale maps used to show property boundaries and land ownership, and are commonly used in land administration in Nigeria. Choropleth maps use shading or colour gradients to represent data values across geographic areas, and are frequently used in environmental and social research. Isoline maps connect points of equal value, such as contour lines for elevation or isohyets for rainfall. In Nigeria, you will encounter vegetation maps produced by NESREA, land degradation maps from NEWMAP, and soil maps from the Federal Department of Agriculture, each serving a distinct environmental management purpose. Understanding which type of map you are working with helps you interpret its content accurately and apply it effectively in your professional practice. Topographic map : A detailed map showing the three-dimensional surface of the earth, including elevation, relief features, rivers, settlements, and land use, represented using contour lines and standardised symbols. In many regions, construction and mining also disturb the soil surface, accelerating erosion. These activities often strip away the protective vegetation cover and alter the natural drainage systems. Fill in the blank: A map that uses shading or colour gradients to represent data values across geographic areas is called a __________ map. Pilot questions 1.1 1. Which of the following best defines a map? 2. A topographic map uses which feature to represent elevation and relief? 3. A map that focuses on the distribution of rainfall across a region is best described as: 4. Cadastral maps are primarily used to show: 5. Isoline maps connect points of: 1.2 Basic Elements of a Map 1.2.1 Title, scale, and north arrow Every well-designed map contains several essential elements that help the reader understand what is being shown. The title identifies the subject and geographic area of the map; without it, the map becomes ambiguous and difficult to use. The scale expresses the relationship between distances on the map and actual distances on the ground. It can be expressed as a representative fraction (for example, 1:50,000, meaning one unit on the map represents 50,000 of the same units on the ground), as a written statement such as "one centimetre to one
LA-NET | ONLINE LEARNING VIDEO PLATFORM FOR POST-SECONDARY & HIGHER INSTITUTION STUDENTS kilometre", or as a graphic scale bar. The north arrow, also called the compass rose, indicates the orientation of the map by showing which direction is north. This is essential for correct navigation and for comparing one map with another. Nigerian topographic maps produced by the Office of the Surveyor-General of the Federation always include all three of these elements so that users can orientate themselves and calculate real-world distances accurately. Fill in the blank: The relationship between a distance on a map and the corresponding distance on the ground is expressed by the map __________. Annotated diagram of a sample map showing the title, scale bar, and north arrow clearly labelled Figure 1.2 Essential elements of a well-designed map 1.2.2 Legend, symbols, and grid references The legend, also called the key, is a panel on the map that explains what each symbol, colour, or pattern represents. Without a legend, the information on the map cannot be correctly decoded. Map symbols are standardised signs used to represent features such as roads, rivers, forests, settlements, and spot heights. Colours are used systematically: blue typically denotes water bodies, green represents vegetation, and brown shading represents elevated terrain on topographic maps. Grid references provide a framework for pinpointing specific locations on a map. A
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